madhav singh on LinkedIn: Title: Building a Simple Pipeline in Node js Node.js Interview Questions

Under each question, you’ll find the approximate answers you should expect to receive. Node.js is a popular server-side platform using which one can build everything, starting from a simple command-line tool to a complex enterprise-level app. It’s a sound reason why there is a demand for an experienced Node.js Developer. You can compare candidates’ knowledge by looking at their easy-to-understand results and then quickly select top candidates for an interview. It also reduces your time-to-hire metrics because you won’t need to screen a single resume. It can speed up application development, improve cloud security, and enhance the reliability of an application’s resources.

  • Node.js is a different technology from Ajax, and each has a different purpose.
  • Since Node.js is by default a single thread application, it will run on a single processor core and will not take full advantage of multiple core resources.
  • This is why you have to ensure your developers know what security threats to expect and how to prevent them.
  • The Cluster module is one of the core Node.js modules and it allows running multiple Node.js worker processes that will share the same port.
  • They handle Node Js development tasks like API integration, server configuration, debugging, and unit testing.

The crypto module is widely used in Node.js applications to generate secure random numbers, create digital signatures, and verify signatures. It also provides support for various encryption algorithms such as AES, DES, and RSA. One of the most important security features in Node.js is the ability to run code in a restricted environment. This is achieved through the use of a sandboxed environment, which can help to prevent malicious code from accessing sensitive data or causing any damage to the system. The Punycode is an encoding syntax which is used to convert Unicode (UTF-8) string of characters to ASCII string of characters. If you want to use it with other Node.js versions, then use npm to install Punycode module first.

What is the purpose of the module.exports?

An event loop in Node.js handles all the asynchronous callbacks in an application. It is one of the most important aspects of Node.js and the reason behind Node.js have non-blocking I/O. Since Node.js is an event-driven language, you can easily attach a listener to an event and then when the event occurs the callback will be executed by the specific listener. Once the entire operation is finished, Node.js receives the output and then executes the callback function.

Node.js Developer interview questions

These can be considered similar to the working of strings and array objects. Streams are used for continuous read/write operations across a channel. But, if the channel is unavailable, all the data cannot be pushed to the memory at once.

What is the difference between operational and programmer errors?

Ideally, you’ll show that you understand and can teach these concepts to someone else. A built-in TCP protocol and the debugging client is provided by Node.js. If you wish to debug your file, you can use the following argument before the name of your JS file which you wish to debug. The DNS module is used for resolving a name and an actual DNS lookup. With this module, it is not required to memorize the IP addresses as the DNS servers convert domain/subdomain into IP addresses.

Node.js Developer interview questions

It allows us to run JavaScript outside of the browser — typically, in a web server. The nmp -Ig-command installs the specific package for your project globally through npm which is the Node.js package manager. It is used when you want to disperse request processing over multiple Node.js processors. Mostly this is done to ramp up the ability to handle more requests per second. Global objects are universal objects that are present in every module or file of the application without requiring explicit import statements.


Go through these top Node.js interview questions and answers that have the highest probability of being asked in an interview. It is the process of reading and writing data to a computer system. Node Js uses a non-blocking I/O model, which allows developers to read and write data asynchronously. This means that the Node Js application can continue to process tasks even when waiting for a response from an external system. Node Js enables web developers to create web applications quickly and easily. It provides an event-driven, non-blocking I/O model for web applications.

Node.js Developer interview questions

If you didn’t get them all, try again tomorrow to see how much you’ve retained. Error-first callbacks are used to pass data and identify if an error has occurred. HTTP status code 504 indicates that the server is unable to process the request. This can be due to several reasons, such as an overloaded server or a network issue. These methods can be used to create, manipulate, and delete objects.

Application Components

The test pyramid is basically a concept that is developed by Mike Cohn. According to this, you should have a higher number of low-level unit tests as compared to high-level end-to-end tests that running through a GUI. ESLint is an open source project initially developed by Nicholas C. Zakas in 2013 which aims to provide a linting utility for JavaScript through a plug. Linters in Node.js are good tools for searching certain bug classes, especially those which are related to the variable scope. MongoDB is a cross-platform, NoSQL, document-oriented database most commonly used with Node.js.

It is a global class that is easily accessible can be accessed in an application without importing a buffer module. So, when dealing with TCP streams or the file system, it’s necessary to handle octet streams. In Node.js, the spawn() is used to launch a new process with the provided set of commands.

For example, if they say that this feature facilitates the development of apps that need to work across multiple platforms, they likely have a good knowledge of Node.js. Candidates should know that Node.js is a cross-platform runtime tool, so developers can run it on several operating systems. They may mention that it runs on macOS, Unix, and Linux and note a few benefits of its cross-platform feature.

Node.js Developer interview questions

We need to go into the package.json and add our custom script within the scripts field. We can then run our script by going to the terminal and running npm run name-of-script. Tell us the skills you need and we’ll find the best developer for you in days, not weeks. This method takes two arguments, the path of the file and the flags. A transform stream is a type of stream that can be used to modify or transform the data as it is being read or written. Two input arguments for asynchronous queue are concurrency value and task function.